Special Purpose Slugs For Use In Ammunition

ABSTRACT

A slug for a firearm cartridge made of plastic. Alternative embodiments have a flat leading end or a stair-stepped leading end. Additional embodiments have a metal insert. The length and diameter of the slugs vary depending on the caliber of the firearm. A preferred embodiment is made from acetal resin (polyoxymethylene).

This application claims priority to U.S. Provisional Application 61/675,607, filed Jul. 25, 2012; U.S. Provisional Application 61/700,688 filed Sep. 13, 2012, and U.S. Provisional Application 61/755,774 filed Jan. 23, 2013, the disclosures of which are incorporated herein by reference.

FIELD OF INVENTION

The field of the invention is slugs for use in cartridges fired from handguns and other firearms.

BACKGROUND

Various types of slugs are used in ammunition. Slugs are made in a variety of shapes and sizes depending upon their intended use. Common types of slugs may be made from lead, jacketed lead, steel (for armor piercing bullets), paper and wax (blanks), rubber (less lethal), and a variety of other materials. The most commonly used slug is made from lead, which can be toxic if it is left in the environment after being discharged from a firearm. In addition, lead is relatively expensive and, thus, costly to use as slug material in firearms.

A lead slug has a certain amount of kinetic energy when it is propelled from the barrel of firearm. The kinetic energy of a discharged slug will be a function of its mass and it velocity via the well-known formula Kinetic Energy (KE)=½ (mass)(velocity)(velocity). [KE=mV2] Assuming the propellant in a firearm cartridge imparts a certain amount force to a slug, a lead slug, due its weight, will be propelled from a firearm with less velocity than a slug with a smaller mass; however, a smaller mass tends to lessen the kinetic energy in accordance with the formula stated above.

Certain kinds of plastic slugs have been made for training purposes; however, they are not in common use for firearms. Lighter plastic slugs have a tendency to arc when expelled from firearms. The arcing affects the accuracy of the shot. For this reason, users have been hesitant to use plastic slugs for personal protection, hunting, or competition shooting.

Delrin® acetal resin (polyoxymethylene), which may be secured from Dupont, is a material that has characteristics that make it possible to use as a slug in firearm cartridges. It is sold in the form of rods (among other forms) of various diameters. It is represented to have the beneficial advantages of creep resistance, strength, stiffness, hardness, dimensional stability, toughness, fatigue resistance, solvent and fuel resistance, abrasion resistance, low wear, and low friction. See the following web site information: http://www2.dupont.com/Plastics/en_US/Products/Delrin/Delrin.html. Delrin® is much less expensive than lead. At the present time, Delrin® is about 5% of the cost of an equal weight of lead.

It would be desirable to make a slug from a non-toxic, smaller mass material that would provide characteristics and qualities equal to or better than lead or other metals. The use of a lighter weight slug would also lessen the “kick” or jump of the firearm and, thus, render shots more accurate. It would also be beneficial to use a less expensive, lighter weight slug, because the velocity of the slug, at shorter ranges, would be higher than the velocity of a lead slug, provided the slug could be made in a configuration and size that would eliminate arcing at common target distances. It would also be beneficial to use a slug that spreads at its leading edge upon impact with the target so that it is more effective in stopping a moving target and less effective in piercing targets at longer ranges so as to prevent damage to targets at longer ranges. It is further desirable to use a slug that is less expensive than lead and more environmentally friendly than lead.

SUMMARY OF INVENTION

Delrin® 150E BK 602 slugs are used in firearm cartridges instead of lead or other metallic slugs. The Delrin® slugs are cut from cylindrical 0.452 inch diameter Delrin® rods to a length of about 0.8 inches or 1.2 inches. The leading end of the Delrin® slugs is not altered once cut; both the front and tail ends of the Delrin® slugs are flat. At short ranges, the Delrin® slugs are propelled at higher velocities than lead slugs and have greater kinetic energy. The leading edge of Delrin® slugs flattens upon impact with the target, is more effective in stopping a moving target, and does not significantly arc at 15, 25, 50, and 75 yards. Muzzle jump (“lick”) affecting accuracy was significantly reduced. The cost of the Delrin® slugs described about is about 5% of the cost of lead slugs. Other types and sizes of Delrin® slugs may be used in different caliber firearms. In addition, other types of plastic material may also be used instead of Delrin® brand products. In alternative embodiments, the slugs may be made with metal inserts or in stepped or telescoping-like shapes to change, alter or customize the performance of the slugs.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross-sectional view of a cartridge used in a firearm.

FIG. 2 is a schematic cross-sectional view of a cartridge with a Delrin® slug.

FIG. 3 is a schematic showing the motion of the firearm and lead and Delrin slugs at 25, 50 and 75 yards.

FIG. 4 is a schematic cross-sectional view of a slug showing an alternative embodiment of the slug containing a metal center.

FIG. 5 is a schematic cross-sectional view of an alternative embodiment of the slug with a stepped shape at an upper end thereof.

FIG. 6 is a schematic cross-sectional view of another alternative embodiment of the slug with a modified stepped shape at an upper end thereof.

DETAILED DESCRIPTION OF INVENTION

FIG. 1 shows a cartridge 1 used in a firearm. The cartridge 1 has a casing 3 that encloses or contains the propellant 5 and a primer 4 that ignites the propellant 5. When the propellant 5 is ignited, the slug 7 is discharged from the casing 1 and propelled to a target.

Various types of plastic and other light weight material were tested and used as slugs 7 in 45 long Colt cartridges 1 fired from a revolver. The tests were made at various target distances. A chronograph was used to determine the speed of the slug 7 at the exit from the firearm and at the target. Standard casings 3, propellants 5, and primers 4 were used in the cartridges 1.

All tests were conducted with one of the following firearms: Ruger® Blackhawk, Ruger® Vaquero, Taurus® Judge, and Taurus® Raging Judge magnum using cartridges having overall lengths of 1.4 inches and 1.76 inches. Other types of firearms and different cartridge lengths may also be used.

The casings 3, propellants 5, and primers 4 were the same for each cartridge shot, namely, a .45 casing, Alliant® Bullseye Smokeless Powder propellant, and large pistol and large rifle magnum primers. Other types of casings 3, propellants 5, and primers 4 may also be used.

Delrin® 150E BK 602 material was purchased in the form of a ½ inch diameter rod. The Delrin® rod was milled to a diameter of 0.452 inches to fit in the casing 3 of the .45 revolver cartridge 1. Delrin® rods may be purchased in specific diameters, so in larger scale uses the Delrin® rods may be purchased with a diameter of 0.452 inches. Other types, styles, and sizes of the Delrin® may also be used, and plastics other than Delrin® brand plastic may also be used. The Delrin® slugs tested were varied at 1 inch, 0.8 inch, and 1.2 inches long. The leading end of the Delrin® slugs was not altered; both the front and tail ends of the Delrin® slugs were flat—i.e., as cut. The preferred length of the Delrin® slugs was 1.2 inches. In addition, other diameter of Delrin may be used for slugs in .44 magnum firearms, 45 caliber firearms, .357 firearms, or other firearms.

The slugs 7 were weighed prior to use by a digital scale; most weight measurements were made on the 0.8 inch length Delrin slugs. The weight of the Delrin slugs was 46 grains and the powder weight averaged approximately 15.6 grains as shown below.

The firearm was held in a Ransom rest and fired by a person. Muzzle displacement (“kick”) was noted on all shots. Chronographs we set at the end of the muzzle and 5, 25, 30, 50 and 75 yards from the muzzle. The distances of the targets from the muzzle of the firearm were varied at 5, 15, 25, 30, 50, and 75 yards. The majority of the bullet speeds were measured at 25 yards from the muzzle.

Comparison shots we made with lead slugs 7 and Delrin®150E BK 602 slugs 7. The comparison lead slugs 7 were standard cowboy loads.

The following speeds were recorded for the 0.8 inch Delrin slug at the following distances from the muzzle, yielding the following Kinetic Energy (KE) calculations:

Distance from Speed in feet Kinetic Slug Length Muzzle per second Energy (KE) 0.8 inches  5 yards 2311 545 0.8 inches 25 yards 1424 207 0.8 inches 30 yards 1224 153 0.8 inches 50 yards 746 56 0.8 inches 75 yards 478 23

The 0.8 inch Delrin slug was x-rayed in tissue and the slug can be seen on an X-ray.

The target materials used were paper, 2×6 inch plywood sheets (white pine and yellow pine), adhesive gel, sheetrock, wood (2×4), and a bullet proof vest (level IIIA). All discharged slugs hit the target within 2 inches of the point of aim. The target impact areas and the slugs were observed, including the depth of penetration of the slugs. Other visible effects on slugs were also noted. The slug penetrations described below were noted:

The 0.8 inch Delrin slug did not penetrate the front of the bullet proof vest when shot at 12 paces from the vest; when a 0.8 inch slug was shot at the rear of vest from the same distance, the slug did penetrate the vest somewhat, but the slug did not go through the vest. When a 2½ inch sheetrock sheet was placed inside the vest, the sheetrock received about 0.3 inches of compaction from the slug pressure. The 0.8 inch Delrin slug penetrated two (2) one-half (½) inch plywood sheets and, thereafter, two (2) one half (½) inch sheets of sheetrock sheets at 25 yards. The 0.8 inch Delrin slug penetrated two (2) one-half (½) inch sheets of sheetrock and then one (1) one-half (½) inch sheets of plywood sheet at 25 yards. The 0.8 inch Delrin slug also penetrated six (60 one-half (½) inch of sheetrock at 25 yards, one (1) one-half (½) inch sheets of plywood at 50 yards, and ⅛ inch of plywood at 75 yards.

A chart of some of the pertinent test results is shown below. In each case, the slug weight was 46 grains.

Bullet Powder Cartridge Ave. Pattern Date Dia. Length Powder Weight Length FPS Dia. Yds KE Aug. 14, 2012 .452″ .8″ Bullseye 15.5 gr 1.4″ 2165 2″   25 478 Jul. 3, 2012 .452″ .8″ Bullseye 15.7 gr 1.4″ 2248 1.25″ 25 516 Jun. 29, 2012 .452″ .8″ Bullseye 15.2 gr 1.4″ 2113 2″   25 456 Jun. 26, 2012 .452″ 1.2″ Bullseye 15.7 gr 1.76″ 2265  1.125″ 25 717 Jun. 26, 2012 .452″ 1.2″ Bullseye 15.7 gr 1.76″ 2214 1″   25 685 Jun. 26, 2012 .452″ 1.2″ Bullseye 15.7 gr 1.76″ 2267  .75″ 25 719

In other tests, a wood (2×4) target was used with a paper target immediately behind the wood target. The 1.2 inch Delrin 150E BK 602 slugs 7 with diameters of 0.452 inches were discharged toward the targets with a .45 long Colt revolver, at 15, 25, and 50 yards. The results of the tests were as follows:

At 15 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 1.5 inches on backside. A paper bulls eye target behind the wooden target had a clean shape/size penetration somewhat resembling the shape of the Delrin® 150E BK 602 slug 7.

At 25 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 3 inches on backside. A paper bulls eye target behind the wooden target had a clean shape/size penetration somewhat resembling the shape/size of the Delrin® slug 7.

At 50 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 5 inches on backside. The paper target behind the wooden target had a clean shape/size penetration, again somewhat resembling the shape/size of the Delrin® slug 7, but producing a hole somewhat larger than the shots at 15 and 25 yards.

The Delrin® slugs did not exhibit any significant arcing or inaccuracy compared to the lead slugs. The depth of penetration of the Delrin® slugs was significantly less than the depth of penetration of the lead slugs. The velocity of the Delrin® slugs was significantly higher than the velocity of the lead slugs. No significant differences in accuracy were noted between the lead and Delrin® slugs 7. The kinetic energy of the Delrin® slugs was significantly higher than that of the lead slugs at the shorter distances.

The Delrin® slugs 7 were deformed on their leading edges after hitting the target, apparently accounting for the shorter penetration distances of the Delrin® slugs. The deformation was “mushroom” shaped. The Delrin® slugs 7 were, otherwise essentially whole after penetration and only slight deformation of the following edge of the Delrin® slugs was noted. No significant fragmentation of the Delrin® slugs 7 was observed.

FIG. 3 is a schematic describing the muzzle jump or kick of the firearm and the path of the Delrin® slugs 7 and the lead slugs. As shown in FIG. 3, the heavier lead slug exited the firearm more slowly than the Delrin® slug 7, causing a muzzle jump that affects the path of the lead slug—i.e., causing the slug to leave the barrel when the barrel was at an elevation slightly higher than its position at the time of firing.

Due to the lighter weight and higher speed of the Delrin® 150E BK 602 slug, the Delrin® slug 7 exited the gun barrel before there was any significant muzzle jump, as shown in FIG. 3. It will be noted that, at the distances tested, the Delrin® slug has a less-arced path than the lead slug.

Several advantages were found to be gained from the use of the Delrin® Slugs 7:

a) The cost of the Delrin® slugs 7 used in the tests was about 5% of the cost of lead slugs, based on weight and then prices current at the time of the tests.

b) The Delrin® slugs 7 did not require any modifications to the leading or trailing edge of the slug once cut.

c) Although the Delrin® slugs 7 used in the tests were milled to 0.452 inches in diameter, Delrin® rods may be ordered in specific diameters, including a 0.452 inch diameter.

d) Muzzle jump (‘kick”) using Delrin® slugs 7 was significantly less than the muzzle jump accompanying the use of lead slugs, increasing the accuracy of the shot.

e) No increased arcing of the Delrin® slugs 7 (as compared to lead slugs) was noted at the distances tested.

f) The “mushroom” shaped deformation of the leading end of the Delrin® slug 7 caused the slug to be stopped more quickly by the target upon impact, making the Delrin® slug 7 safer for enclosed spaces (aircraft and homes, for example) and safer for outdoor spaces where a slug passing through the target could impinge upon unintended objects or people after passing through the target.

g) The Delrin® slugs 7 did not significantly disintegrate or fragment upon impact, making them easier to retrieve from the target and less like to contaminate game when used for hunting.

h) In human combat/protection applications, the Delrin® slug 7, due to its deformation upon impact, appeared more likely to stop an intruder/opponent and less likely to travel through the intruder and endanger other persons or property.

i) The lighter weight of the Delrin® slug 7 allowed it to travel significantly faster to the target; in the tests conducted, the speeds of all of the Delrin® slugs greatly exceeded that of the lead slugs.

j) Due to the increase speeds of the Delrin® slugs 7, and despite the significantly decreased weight of the Delrin® slugs 7, the kinetic energy of the Delrin® slugs 7 was significantly higher than that of the lead slugs at the distances tested.

k) The use of Delrin® slugs 7 would not pollute the environment with lead, as would be the case with lead slugs.

l) Damage to the target was greater when impacted by the Delrin® slug 7 than when impacted by the lead slug; thus, the Delrin® slug 7 would appear to be more effective in stopping a moving target than lead at the distances tested.

It is understood that the same or other types of plastics may be used for slugs in different caliber fire arms, and that the length, diameter, and shape of the slug may vary depending on the type of firearm and cartridge used.

In an alternative embodiment shown in FIG. 4, copper or other metal may be inserted in a Delrin® slug 8. In this embodiment, the Delrin® slug 8 is made as described above. A central longitudinal hole 9 is then made in the Delrin® slug 8. In the slug 8 that was made and tested, the Delrin slug was 1 inch long. A 0.5 inch long, 0.25 inch diameter, hole 9 was drilled in the leading end of the slug 8. A copper insert 11 was placed in the hole until it was flush with the leading end of the Delrin® slug 8. As above, other plastic materials may be used instead of Delrin®. The slug 8 may be encased in a cartridge (not shown).

Although copper was used in the test referenced above, other metals, such as steel or lead, could be used as the insert instead of copper. There are also various ways the metal can be inserted into the Delrin® slug. For example, the metal may be heat softened and placed in the Delrin® slug, extruded into the slug 8, screwed into the slug, inserted with pressure of force, or placed in the slug 8 by other means known in the art.

The depth and diameter of the hole depends on the length and diameter of the Delrin® slug 8, which, in turn depends on the size of the cartridge 1 needed for the firearm from which the slug 8 with the metal insert 11 is to be propelled.

When fired from a firearm, the Delrin® slug 8 with the copper insert 11 carried downrange about 200 yards—farther than the Delrin® slug 7 without the copper insert.

Further in the alternative, the metal insert 11 may extend beyond the leading end of the Delrin slug 8. In such applications the Delrin® slug 8 may be made so that it is dislodged from the metal 11 at the time it exits the barrel of the firearm and, thus, perform in the nature of a Sabot bullet. Such Sabot-like small caliber bullets may then be used in firearms with larger bores.

Further, in applications using a metal insert 11, the extra weight of the bullet due to the metal is believed to render the bullet as “non-armor piercing.”

In another embodiment shown in FIG. 5, a Delrin® slug 12 has a leading end 13 that is stair-stepped or telescoping shape 14. A base end 15 is 0.5 inches in diameter and 1 inch high. The overall length of the Delrin® slug 12 is 1.2 inches. A first step 16 from the base is 0.4 inch in diameter and 0.1 inches high. A second step 17 is 0.3 inches in diameter and 0.1 inches high. The first and second steps 16 and 17 are formed from an initial slug that is 1.2 inches high and 0.5 inches in diameter. The steps 16 and 17 are formed from the initial slug 12 by turning the slug 12 on a lathe and cutting the steps 16 and 17 in to the initial slug 12; however, the entire slug 12 could be injection molded if desired. The slug 12 used in tests described below weighed 76 grains. The slug 12 could also be made with a central longitudinal hole into which a copper or other metal insert may be placed, if desired. (not shown) The slug 12 may be encased in a cartridge (not shown).

In a further embodiment shown in FIG. 6, a Delrin® slug 18 has a leading end 19 that is stair-stepped or telescoping shape 20. A base end 21 is 0.5 inches in diameter and 1 inch high. The overall length of the Delrin® slug 18 is 1.4 inches. A first step 22 from the base is 0.4 inches in diameter and 0.2 inches high. A second step 23 is 0.3 inches in diameter and 0.2 inches high. The first and second steps 22 and 23 are formed from an initial slug 18 that is 1.4 inches high and 0.5 inches in diameter. The steps 22 and 23 are formed from the initial slug 12 by turning the slug 18 on a lathe and cutting the steps 22 and 23 in to the initial slug 12; however, the entire slug 18 could be injection molded if desired. The slug 18 used in tests describe below weighed 83 grains. The slug 18 could also be made with a central longitudinal hole into which a copper or other metal insert may be placed, if desired. (not shown) The slug 18 may be encased in a cartridge (not shown).

The slugs 7 (flat end), 12 (each step 0.1 inch high), and 18 (each step 0.2 inches high) were tested by firing from a 500 magnum firearm. The target consisted of 6 inches of cardboard in front of a ¾″ inch piece of plywood, which, in turn was in front of target rubber. The target was 25 yards from the firearm. Speed was measured at 5 yards from the firearm, and kinetic energy was calculated using the speed so determined.

The test results are summarized below:

Weight Speed Kinetic Slug (grains) (ft/sec) Energy Target Penetration 7 70 2443 927 Fully penetrated cardboard; dented plywood 12 76 2588 1130 Fully penetrated cardboard and plywood; bounced off rubber 18 83 2592 1240 Fully penetrated cardboard and plywood; sunk into rubber

Upon impact with the target slugs 12 and 18 spread out later than slug 7. In general terms, it appeared that the flatter the forward end of the slug, the less penetration, and the greater the speed, the greater the kinetic energy.

It is understood that, although this application references handguns, the special purpose slugs described could also be made to fit and be used in rifles, as well. In addition, although reference is frequently made to the Delrin® slugs, other type of plastics could also be used. 

It is claimed as follows:
 1. A firearm cartridge having an acetal resin (polyoxymethylene) slug.
 2. The firearm cartridge of claim 1 wherein the material used for the slug is Delrin® 150E BK
 602. 3. The firearm cartridge of claim 1 wherein the slug is 0.452 inches in diameter.
 4. The firearm cartridge of claim 1 wherein the slug is 1.2 inches in length.
 5. The firearm cartridge of claim 1 wherein the slug has a flat leading edge.
 6. The firearm cartridge of claim 1 wherein the slug has a flat trailing edge.
 7. The firearm cartridge of claim 1 wherein the slug is 0.8 inches in length.
 8. The firearm cartridge of claim 1 wherein the slug has a diameter sufficient for at least one of a .44 magnum firearm, 45 caliber firearm, a 500 magnum firearm, and a .357 firearm.
 9. A slug for use with a firearm comprising: (a) a slug made of acetal resin (polyoxymethylene); (b) the slug having a length of about 1.2 inches; and (c) the slug having a diameter of about 0.452 inches.
 10. The slug of claim 9 wherein the material used for the slug is Delrin® 150E BK
 602. 11. The slug of claim 9 wherein the slug has a flat leading edge.
 12. The slug of claim 9 wherein has a flat trailing edge.
 13. The firearm cartridge of claim 9 wherein the slug has a diameter sufficient for at least one of a .44 magnum firearm, a 45 caliber firearm, a 500 magnum firearm, and a .357 firearm.
 14. A slug for use with a firearm comprising: (a) a slug made of plastic material; (b) the slug having a length suitable for a cartridge fitting in a firearm; (c) the slug having a diameter suitable for a cartridge fitting in a firearm;
 15. The slug of claim 14 wherein the slug is made from Delrin® 150E BK
 602. 16. The slug of claim 14 wherein the slug has a length of 1.2 inches.
 17. The slug of claim 14 wherein has a diameter of 0.452 inches.
 18. The slug of claim 14 wherein the slug has a flat leading edge and a flat trailing edge.
 19. The slug of claim 14 wherein the slug has a length of 0.80 inches.
 20. The firearm cartridge of claim 14 wherein the slug has a diameter sufficient for at least one of a .44 magnum firearm, 45 caliber firearm, a 500 magnum firearm, and a .357 firearm.
 21. A slug for use with a firearm comprising: (a) a plastic slug, the slug having a central longitudinal hole and a length and diameter suitable for fitting in a firearm; (b) an insert slug made of metal, the insert slug placed in the hole in the plastic slug;
 22. The slug of claim 21 wherein a leading end of the insert slug is flush with a leading end of the plastic slug.
 23. The slug of claim 21 wherein the plastic slug is made of Delrin® 150E BK
 602. 24. The slug of claim 21 wherein the insert slug is made of copper.
 25. The slug of claim 21 wherein a leading end of the insert slug extends forward from the slug.
 26. The slug of claim 25 wherein the plastic slug is dislodged from the insert slug when the plastic slug exits a barrel of the firearm.
 27. The slug of claim 21 wherein the plastic slug has a flat leading end.
 28. The slug of claim 21 wherein the insert slug has a flat leading end.
 29. The slug of claim 21 wherein the plastic slug is 1 inch in length and the insert slug is ½ inch in length.
 30. The slug of claim 21 wherein the insert slug has a 0.25 inch diameter.
 31. A slug for use with a firearm comprising: a slug made of plastic, the slug having a base and a leading end opposite the base, the leading end having a first step and a second step.
 32. The slug of claim 31 wherein the slug is made of acetal resin (polyoxymethylene).
 33. The slug of claim 31 wherein the slug is made of Delrin® acetal resin (polyoxymethylene).
 34. The slug of claim 31 wherein the base of the slug is 0.5 inches in diameter.
 35. The slug of claim 31 wherein the first and second steps are formed by a lathe.
 36. The slug of claim 31 wherein the slug is formed by injection molding.
 37. The slug of claim 31 wherein the first step is 0.1 inches high and 0.4 inches in diameter, the second step is 0.3 inches in diameter and 0.1 inches high, and the overall length of the slug is 1.2 inches.
 38. The slug of claim 31 wherein first step is 0.2 inches high and 0.4 inches in diameter, the second step is 0.2 inches high and 0.3 inches in diameter, and the overall length of the slug is 1.4 inches.
 39. The slug of claim 31 wherein the slug forms a central longitudinal hole.
 40. The slug of claim 39 wherein an insert slug is placed in the central longitudinal hole.
 41. The slug of claim 31 wherein the slug is encased in a cartridge. 